Students take part in a lot of outdoor activities.

a. Do OC là tia phân giác của góc xOy, nên góc COA = góc COB. 
--> Do CA vuông góc với OA và CB vuông góc với OB, nên góc OCA = góc OCB = 90 độ. 
--> Vì vậy, tam giác OCA và tam giác OCB là hai tam giác đồng dạng. 
=> Do đó, OA = OB.
b. Lấy D thuộc tia Ot (D không thuộc C). 
--> Do OD là tia phân giác của góc AOB, nên góc AOD = góc BOD. 
--> Do AD vuông góc với DA và BD vuông góc với DB, nên góc ODA = góc ODB = 90 độ. 
--> Vì vậy, tam giác ODA và tam giác ODB là hai tam giác đồng dạng. 
=> Do đó, DA = DB.
c. Do DA = DB (đã chứng minh ở phần b) và góc AOD = góc BOD, nên OD là tia phân giác của góc AOB theo định nghĩa của tia phân giác.

1-c

2-d

3-d

4-a

5-c

1. C
2. A
3. D
4. A
5. C

1. Ha Long Bay has about 1.969 islands
=> There are approximately 1.969 islands in Ha Long Bay.
2. My old laptop is not as expensive as my new one
=> My old laptop is less expensive than my new one.
49. It is good for students to learn in groups and share their ideas.
50. Students at my school must wear a uniform every school day.

1->There are about 1969  islands in Ha Long Bay

giups minhf nha

=> My sister was happy because there was a lovely present from her old friend for me.

Giúp mình với

Đáp án:

B. Champion

1. in/ is/ held / August/ La Tomatina/ every year.

        🡲         La Tomatina is held in August every year

2. last year/ 60,000/ attended/ About/people/ festival/ the

        🡲         About 60000 people attended the festival last year

3. went/ the/ to/ Flower Festival/ We/ Da Lat/ last year

        🡲         We went to the Flower Festival in Da Lat last year 

4. decorate/ During/ the Vietnamese/ Tet, / with/ their/ houses/ peach blossoms

        🡲         During Tet, the Vietnamese decorate their houses with peach blossoms

5. painting / children / Easter eggs / enjoy / At Easter,

        🡲         At Easter, children enjoy painting Easter eggs

6 it/ a/ celebrate/ People/ special/ in/ way

        🡲         People celebrate it in a special way

7. costumes/ People/ wear/ parade/ and/ through/ the streets/traditional.

        🡲         People wear traditional costumes and parade through the streets

8. Halloween / prepare / People / for/ candy apples

        🡲         People prepare apples candy for halloween

9. with / people / cornbread /  a feast / turkey,/ sweet potatoes./For Thanksgiving / have / and

        🡲         For Thanksgiving people have a feast with turkey, conbread and sweet potatoes

10. is/ This/ festival/ two/ every/ held/ years

        🡲         This festival is held every two years

1 D

2 B

3 A

4 C

5 D

1 C

2 B

3 D

4 C

5 D

1 When her mother was cooking, her little baby woke up and cried out

2 We go to the discount store because it sells products at lower prices

3 Although my grandfather is very old, he is still young at heart

4 After he had cleaned his house, his friends came

5 Because of the danger of Acid rain, trees's leaves are damaged

HELP MEEEE